/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.disklru.ui;

import android.annotation.SuppressLint;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.DisplayMetrics;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.view.WindowManager.LayoutParams;
import android.widget.Toast;

import com.example.disklru.R;
import com.example.disklru.provider.Images;
import com.example.disklru.util.DiskLruCache;
import com.example.disklru.util.ImageCache;
import com.example.disklru.util.ImageFetcher;
import com.example.disklru.util.ImageResizer;
import com.example.disklru.util.ImageWorker;

public class ImageDetailActivity extends FragmentActivity implements OnClickListener {
    private static final String IMAGE_CACHE_DIR = "images";
    public static final String EXTRA_IMAGE = "extra_image";

    private ImagePagerAdapter mAdapter;
    private ImageResizer mImageWorker;
    private ViewPager mPager;

    @SuppressLint("NewApi")
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.image_detail_pager);

        // Fetch screen height and width, to use as our max size when loading images as this
        // activity runs full screen
        final DisplayMetrics displaymetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        final int height = displaymetrics.heightPixels;
        final int width = displaymetrics.widthPixels;
        final int longest = height > width ? height : width;

        // The ImageWorker takes care of loading images into our ImageView children asynchronously
        mImageWorker = new ImageFetcher(this, longest);
        mImageWorker.setAdapter(Images.imageWorkerUrlsAdapter);
        mImageWorker.setImageCache(ImageCache.findOrCreateCache(this, IMAGE_CACHE_DIR));
        mImageWorker.setImageFadeIn(false);

        // Set up ViewPager and backing adapter
        mAdapter = new ImagePagerAdapter(getSupportFragmentManager(),
                mImageWorker.getAdapter().getSize());
        mPager = (ViewPager) findViewById(R.id.pager);
        mPager.setAdapter(mAdapter);
        mPager.setPageMargin((int) getResources().getDimension(R.dimen.image_detail_pager_margin));

        // Set up activity to go full screen
        getWindow().addFlags(LayoutParams.FLAG_FULLSCREEN);

        // Enable some additional newer visibility and ActionBar features to create a more immersive
        // photo viewing experience
//        if (Utils.hasActionBar()) {
//            final ActionBar actionBar = getActionBar();
//
//            // Enable "up" navigation on ActionBar icon and hide title text
//            actionBar.setDisplayHomeAsUpEnabled(true);
//            actionBar.setDisplayShowTitleEnabled(false);
//
//            // Start low profile mode and hide ActionBar
//            mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE);
//            actionBar.hide();
//
//            // Hide and show the ActionBar as the visibility changes
//            mPager.setOnSystemUiVisibilityChangeListener(
//                    new View.OnSystemUiVisibilityChangeListener() {
//                        @Override
//                        public void onSystemUiVisibilityChange(int vis) {
//                            if ((vis & View.SYSTEM_UI_FLAG_LOW_PROFILE) != 0) {
//                                actionBar.hide();
//                            } else {
//                                actionBar.show();
//                            }
//                        }
//                    });
//        }

        // Set the current item based on the extra passed in to this activity
        final int extraCurrentItem = getIntent().getIntExtra(EXTRA_IMAGE, -1);
        if (extraCurrentItem != -1) {
            mPager.setCurrentItem(extraCurrentItem);
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
//            case android.R.id.home:
//                // Home or "up" navigation
//                final Intent intent = new Intent(this, ImageGridActivity.class);
//                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
//                startActivity(intent);
//                return true;
            case R.id.clear_cache:
                final ImageCache cache = mImageWorker.getImageCache();
                if (cache != null) {
                    mImageWorker.getImageCache().clearCaches();
                    DiskLruCache.clearCache(this, ImageFetcher.HTTP_CACHE_DIR);
                    Toast.makeText(this, R.string.clear_cache_complete,
                            Toast.LENGTH_SHORT).show();
                }
                return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.main_menu, menu);
        return true;
    }

    /**
     * Called by the ViewPager child fragments to load images via the one ImageWorker
     *
     * @return
     */
    public ImageWorker getImageWorker() {
        return mImageWorker;
    }

    /**
     * The main adapter that backs the ViewPager. A subclass of FragmentStatePagerAdapter as there
     * could be a large number of items in the ViewPager and we don't want to retain them all in
     * memory at once but create/destroy them on the fly.
     */
    private class ImagePagerAdapter extends FragmentStatePagerAdapter {
        private final int mSize;

        public ImagePagerAdapter(FragmentManager fm, int size) {
            super(fm);
            mSize = size;
        }

        @Override
        public int getCount() {
            return mSize;
        }

        @Override
        public Fragment getItem(int position) {
            return ImageDetailFragment.newInstance(position);
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            final ImageDetailFragment fragment = (ImageDetailFragment) object;
            // As the item gets destroyed we try and cancel any existing work.
            fragment.cancelWork();
            super.destroyItem(container, position, object);
        }
    }

    /**
     * Set on the ImageView in the ViewPager children fragments, to enable/disable low profile mode
     * when the ImageView is touched.
     */
    @SuppressLint("NewApi")
    @Override
    public void onClick(View v) {
//        final int vis = mPager.getSystemUiVisibility();
//        if ((vis & View.SYSTEM_UI_FLAG_LOW_PROFILE) != 0) {
//            mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_VISIBLE);
//        } else {
//            mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE);
//        }
    }
}
